WO2015032417A1

WO2015032417A1 - Activating button with integrated noise generator and smoke detector comprising said noise generator

Info

Publication number: WO2015032417A1
Application number: PCT/DK2014/050277
Authority: WO
Inventors: Glenn HØJMOSE
Original assignee: Cavius Aps
Priority date: 2013-09-09
Filing date: 2014-09-09
Publication date: 2015-03-12
Also published as: GB2517975A; GB201315967D0

Abstract

The present invention describes an activating button with an integrated sound/noise generator, where said button comprises a ventilated bottom plate having one or more apertures; an activating member, which has at least one activating means arranged on an underside of said activating member's top surface, which activating means may be brought into contact with at least one contact point, and where said activating member' s top surface is provided with an aperture; a sound/noise generator having a sound chamber delimited by a piezo electrical loudspeaker element and the underside of the top surface of the activating member, and the piezo electrical loudspeaker element and the ventilated bottom plate allowing access to an inner volume of the device in which the sound button is integrated such that sound may escape through the aperture in the top surface and the ventilated bottom plate and into the device and to the ambient surroundings, where said piezo electrical loudspeaker is arranged above the bottom plate; and an electrical connection between said contact point and said piezo electrical loud-speaker. Furthermore the invention presents the novel sound button integrated into a smoke alarm and a temperature alarm. The method by which the noise generator is integrated is also disclosed, namely such that the noise generator is completely ventilated, which facilitates that a very loud alarm noise may be generated from a relatively small device.

Description

ACTIVATING BUTTON WITH INTEGRATED NOISE GENERATOR AND SMOKE DETECTOR COMPRISING SAID

NOISE GENERATOR

Field of the Invention

The present invention relates to an activating button with an integrated sound/noise generator as well as a smoke detector in which an activating button according to the 5 invention is incorporated. Furthermore, a heat alarm incorporating an activating button according to the invention is also disclosed.

Background of the Invention

In a number of devices such as smoke detectors, heat detectors, gas detectors etc. without limitation it is often a requirement that it must be possible to test the device

10 without actually exposing it to the condition to which it is designed, i.e. smoke, heat etc. For this reason most devices are provided with a button such that during the test phase the button may be activated and the alarm generated. Naturally, these types of test can only indicate whether or not the alarm generator, i.e. the sound/noise generator or light emitting devices are functioning properly, but do not indicate anything

15 about the sensor's ability to react to the exposure to which it is designed. Typically, the activating button will be placed on the side of the device and the sound/noise generator provided in a position where it is possible to allow substantially free emission of sound/noise from the device. For these reasons the devices are often provided with gills allowing the sound/noise to escape. These constructions often require a substan-

20 tial volume in order to be able to fit all the components of the device inside the device itself and allow a safe and secure functioning of the device. Naturally, the drawback of this is that the sensors often are not welcome in an interior decoration scheme, as they are often detrimental to the design.

25 In other technical fields it is known to create sound buttons, by building loudspeaker units into the button as such. One such example is disclosed in US2003/0107549. The object here is to follow the trend of personal electronics, and without increasing the size of the device provide a loudspeaker. The loudspeaker is built into a four-way button. With reference to the devices to which the construction is directed, it is clear that

30 the object in addition to maintain the devices sizes or being free to design devices without having to accommodate a loudspeaker, is to be able to transmit a (reasonable) sound quality regarding speech and music. In order to achieve this the loudspeaker is built into a volume limited by the buttons upper and lower lids, provided sound chests (resonance spaces) above and below the loudspeaker element. A further example is known from US2003/0107549- from the same applicant as US2007/0017792. The construction is similar to the previous one, but in this publication the button is a five-way button. The audio quality should be improved by providing larger acoustic cxhests (resonance volumes). For this purpose the interior body of the device, as well as a small space above the loudspeaker, and the apertures connect- ing these two volumes is decisive in determining the sound quality. These volumes are in combination with the traditional loudspeaker construction, i.e an electromagnetic drive unit connected to a moveable membrane (in the volumes) required in order to be able to transmit quality audio.

Object of the Invention

Consequently, it is an object of the present invention to be able to provide a very compact activating button incorporating a sound/noise generator such that the devices may be designed smaller and yet provide added efficiency. A major difference between the requirements of the present invention and those addressed by the prior art recited above is the fact that whereas loudspeaker constructions designed to broadcast speech or music will have certain quality requirements, the present invention has to address requirements relating to the level of noise. An alarm signal must be sufficiently loud, often fulfilling requirements laid down by national law, such that as the alarm is activated, it will be sufficiently safe to assume that either people present (even asleep) or in the vicinity will notice the noise. The prior art devices broadcasting speech or music are not required to noise volumes of required magnitude. Particularly for personal electronics the need to be able to broadcast loudly is very limited. This naturally, together with different requirements - noise vs quality of broadcast, makes for different constructions.

Description of the Invention

The invention addresses this by providing an activating button with an integrated sound/noise generator, where said button comprises: a ventilated bottom plate having one or more apertures;

at least one contact point arranged on said bottom plate;

an activating member, which activating member has at least one activating means arranged on an underside of said activating member's top surface, which activating means may be brought into contact with the at least one contact point, and where said activating member's top surface is provided with an aperture,

a sound/noise generator having a sound chamber delimited by a piezo electrical loudspeaker element and the underside of the top surface, and the piezo electrical loudspeaker element and the ventilated bottom plate allowing access to an inner volume of the device in which the sound button is integrated such that sound may escape through the aperture in the top surface and the ventilated bottom plate and into the device and to the ambient surroundings, where said piezo electrical loudspeaker is arranged above the bottom plate; e. an electrical connection between said contact point and said piezo electrical loudspeaker.

The button may be built into a variety of devices and as such it is necessary to provide a ventilated bottom such that the button may be moved upwards and downwards and ensure that the sound/noise generator in the shape of a piezo electrical loudspeaker is not positioned in a closed base, but due to the ventilated bottom plate, and the aperture in the activating member, the piezo electrical loudspeaker element is able to move substantially freely in response to an activating current. By furthermore providing a contact point on the base plate such that the activating button is a contained unit where it is only necessary to provide an electrical connection and electrical energy, the proper arrangement of the button is left entirely to the designer as both the activating button and the sound/noise generation is provided in a self-contained unit. The activating member which is the member which will be ma- nipulated/depressed during testing or operation is provided with an activating member which is brought into contact with a contact point during activation such that an electrical circuit is closed and the sound/noise generator activated. The piezo electrical loudspeaker is arranged above the bottom plate, but below the top surface of the activating member. In a further advantageous embodiment of the invention the activating means is in the shape of one or more pins projecting from the underside of the top surface of the activating member, towards the bottom plate, and where spring means are arranged for biasing the activating means away from the bottom plate, where means are provided delimiting the activating member's travel relative to the bottom plate, such that the spring means when the button is not activated urges the activating member into a position furthest away from said bottom plate. The springs ensure that the activating member, and the one or more pins, are urged away from the contact point in order to avoid unnecessary contact and thereby activation of the device in which the activating button is arranged.

In a still further advantageous embodiment of the invention the button in a plain view is circular, oval, polygonal or any other geometrical shape, and a light element is pro- vided along the periphery of the button. Typically, the light element will be integrated with the button as such, such that as the button is depressed also the light element will be depressed. The light element may also however be a separate element not moving with the activating means. The advantage here being that the light transmitting means, for example in the shape of LED' s may be arranged in constant contact with the light element, whereas in the embodiments where the light element moves with the activating member, the light transmitting means will also move, and as such needs to be brought into (or almost into) contact with the light source - typically LED's. As is evident from a further advantageous embodiment of the invention the light element is made from a light transmitting material, which light element has light conducting pins extending towards the bottom plate, and where close to or adjacent distal ends of the light conducting pins LED elements are provided.

By arranging the LED elements, for example on the base plate, and bringing the pins extending from the light element towards the base element into contact or almost con- tact (that is to be understood as light transmitting contact) with the LEDs, the pins will guide the light to the light element provided along the periphery of the button. In this manner a relative simple light transmission construction is provided with a large degree of freedom for the exterior design of the light emitting device such that it may fit any shape and curvature desired in the design of the activating button. In a further advantageous embodiment the aperture comprises one or more openings, and where said openings are arranged in a position making it possible to vacuum clean the interior of the device through said openings. By providing more than one aperture it is possible to create an airflow through the activating button such that any dust or the like being collected inside the activating button, i.e. in the space between the piezo electric elements and the top surface may be removed simply by connecting a vacuum cleaner to some of the openings in the aperture thereby creating a strong underpressure in this space and consequently an airflow through the openings both in and out removing dust etc.

As the proper workings of the activating button is of the utmost importance and this together with the desire to create as small and compact a button as possible the possibility to clean the button and especially the spaces between the active parts of the but- ton is very important.

The invention is also directed to a smoke detector having at least one internal chamber, which chamber has at least one opening towards the surroundings, such that air may pass through the chamber, and where means are provided for emitting light and means for detecting said light is provided in or around said chamber, where the change in light intensity registered by the means generates a smoke alarm, by means of a noise and/or light generating means and where the internal chamber is substantially circular, and that the light emitting means are arranged at an angle to the light detecting source, where along the periphery of the chamber a plurality of air foils are arranged, where the airfoils substantially have a cross-sectional shape corresponding to an airplane wing with one side of the air foils flat and the other side being provided with a curvature, and where said airfoils are arranged at an angle relative to an imaginary radius of the internal chamber, and where said noise generating means are provided in a activating button as described above.

The smoke detecting chamber is in this embodiment arranged just below the activating button such that the bottom plate of the activating button is delimiting the smoke detection chamber. Further installations relating to the smoke detector such as for exam- pie batteries and potentially communication modules may be integrated below the smoke detection chamber.

In a further advantageous embodiment of the invention a special constellation of the smoke detector is provided where said smoke detector has a base plate, suitable to be mounted in a holder or directly on a surface, wherein substantially centrally in the smoke detector a through-going opening is provided, where said opening comprises a first pipe section arranged substantially perpendicular to said base plate, and coaxially with said first pipe section the top surface of the activating button is provided with a second pipe section extending towards the base plate where said first and second pipe sections overlap and are displaceable along the pipes' axis.

In this manner it becomes possible to integrate the smoke detector in a ceiling rose by providing the through-going opening allowing the wire of the light fixture or lamp to pass through the smoke detector. The smoke detector in this embodiment therefore at the same time provides a cover for the light fixture connection box typically integrated in the ceiling structure and a smoke detector. In this embodiment it is contemplated that the smoke detector may be provided with a battery, i.e. with its own power source, but also be connected to the mains such that an integrated transformer will create the energy supply for the sound/noise generating device etc.

A combination is also contemplated where the mains when the light is switched on will charge a battery in the smoke detector thereby refurbishing the energy supply at regular intervals, i.e. at the same intervals as the lights are turned on.

The invention is also directed at a temperature alarm having all the advantageous features of the activating button where the temperature alarm incorporates such an activating button and where a temperature probe extends from said top surface, and where protective buttresses converge from the periphery of the top surface to a central pro- tective member overlying the temperature probe.

In this embodiment the protective buttresses provide protection for the temperature probe which extends from the top surface of the activating button. By providing the buttresses the temperature probe remains in a substantially free exposure to the ambi- ent environment and may therefore be able to very quickly and accurately detect any temperature changes in the ambient environment. The temperature probe will typically send information to a control unit where the input is registered and appropriate output generated. For example the absolute temperature may be registered and if the absolute temperature around the temperature probe falls within a certain interval the alarm is activated. Alternative an increase in temperature over time may also within certain limits generate an output setting off the alarm.

As should be evident from the advantageous embodiments the method of using the noise generating element in a button according to a preferred embodiment of the invention where the method provides an alarm device with a noise generator, where said noise generator is integrated in a button device built into the alarm device, where said noise generator is a substantially flat piezo electrical element arranged in a sound chamber, said sound chamber having ventilation on both planar surfaces of the piezo electrical element.

Description of the Drawing

The invention will now be explained with reference to the accompanying drawings wherein

Figure la and lb illustrate an activating button integrated in a smoke alarm

Figure 2 illustrates a cross section through the smoke alarm

Figure 3 illustrates the activating pins and light transmitting pins

Figure 4 illustrates the smoke alarm seen from below

Figure 5 illustrates the light emitting element

Figure 6 illustrates figure 5 where the piezo electrical element has been removed in order to expose the ventilated bottom plate Figure 7 illustrates a further embodiment of the invention

Figure 8 illustrates the invention where the top part of the smoke detector is removed

Figure 9 illustrates the same features as are depicted in figure 8, but from a slightly different angle and in a cross section Figure 10 illustrates a further embodiment of the invention Figure 11 illustrates a further embodiment of the invention

Detailed Description of the Invention

In figures la and lb is illustrated an activating button integrated in a smoke alarm 10. In figure la the smoke alarm is installed in a holder 11 and in figure lb the smoke alarm is removed from the holder whereby the underside 12 of the smoke alarm is visible.

On a top surface 13 of the smoke alarm is arranged an activating button 1 as will be described in more detail below. In this embodiment the activating button 1 has a cen- trally placed aperture 2 providing access to the interior of the activating button 1, but substantially separated from the smoke alarm as such. Coaxially, and in the same plane as the activating button 1, is arranged a light emitting member 3. In this embodiment the activating button is substantially circular and the light emitting member 3 has the same geometrical shape thereby providing a substantially flush top surface. It is of cause possible to provide the button in any geometrically shape, and also within the invention it is contemplated that either the activating member or the light emitting member may be raised relative to the other if desired. By depressing the activating button 1 the light emitting member 3 and the activating button is brought out of the plane of the top surface 13, but will otherwise remain in the same plane as the top sur- face and thereby constitute a substantially flush top surface.

The smoke alarm itself is arranged below the activating button and the mesh 14 in addition to allowing the ambient air to flow through the smoke alarm also shields off the lower parts of the activating button and the smoke chamber as such.

Below the smoke chamber arranged behind the mesh 14 are provided various electronics and a battery 15 as is visible in figure lb.

Figure 2 illustrates a cross section through the smoke alarm described above with ref- erence to figures la and lb where the various features of the invention implemented in a smoke alarm may be deducted. The activating button 1 including the aperture 2 is arranged uppermost in the cross section. The activating button 1 comprises a ventilated bottom plate 4 which bottom plate 4 in this embodiment is integral with a frame element 5 which frame element surrounds the activating member 6 and the light emitting member 3. The activating member 6 is provided with activating means 7 arranged on an underside of the top surface of the activating member. The activating means 7 extends downwards relative to the top surface of the activating member and a contact point 8 is superposed the activating means 7 such that by depressing the activating button and thereby the top surface 6 of the activating member the activating means 7 may be brought into contact with the contact point 8 thereby closing a switch and generating an alarm signal.

Between the ventilated bottom plate 4 and the activating member 6 is provided a sound/noise generator 9 which typically will be in the shape of a piezo electrical loudspeaker element. Between the loudspeaker element 9 and the activating member 6 is created a sound chamber 20. When an alarm is generated, i.e. the switch 8 is closed, the piezo electrical element 9 will begin to vibrate, typically moving up and down. Due to this movement the ventilated bottom element 4 due to the apertures 21 (ventilation) provided in the bottom element will not give any significant air resistance and as such it is ensured that the piezo electrical element is not hampered in its effort to generate the alarm signal. The alarm signal will escape through the aperture 2 provid- ed in the activating member 6, and in this manner a very compact and yet very effective activating button incorporating a sound/noise generator is provided.

The length of the activating means 7 may obviously be varied according to the task in that the length of the activating means 7 provides the room in this example for a smoke chamber 30 which is arranged between the ventilated bottom plate 4 and the electronics 22 and other necessary equipment such as battery etc. arranged below the smoke chamber.

The activating button in this embodiment is also provided with a light element 3 made from a light transmitting material. The light element has light conducting pins 23 extending downwards relative to the activating button's top surface such that the light conducting pins 23 extend towards the bottom plate 24. On the bottom plate 24 is arranged LED elements such that the distal ends of the light conducting pins 23 may be brought into sufficient contact with the LEDs 25 in order that light may be transmitted through the light conducting pins 23 and distributed and diffused in the light element 3 on the surface of the activating button 1.

The activating means 7 are further provided with biasing means, in this embodiment a helical string 26 arranged coaxially with the activating means in order to urge the activating member 6 away from the contacts 8.

Fig. 3 illustrates the same features as described with reference to fig. 2, however from a different view, especially elucidating the relationship between the activating means 7, the light conducting pins 23 and the contacts 8 and LED's 25 arranged on the bottom plate.

In figure 4 the smoke alarm is illustrated seen from below. The top of the smoke chamber is in this embodiment the bottom plate 4 provided with apertures allowing the piezo electrical element 9 (see figure 2) to move freely. The smoke chamber comprises a substantially circular internal chamber 31 where a number of openings are provided from the internal chamber 31 to the outside allowing air to drift through the internal chamber. Inside the chamber means are provided for emitting light 32 and means for detecting said light is provided at an angle and hidden by a wall 34 relative to the light emitting means 32. A change in the light intensity will be detected by the light detecting means which according to how the smoke alarm is programmed may generate an alarm thereby activating the piezo electrical element 9. Along the periphery of the internal chamber 31 and at an angle to an imaginary radius are arranged a plurality of air- foils 35 where the air- foils 35 substantially have a cross-sectional shape corresponding to an aeroplane wing, i.e. one side of the air- foil is flat 35' whereas the other side is provided with a curvature 35" . This shape of the air- foil has proven to provide minimum resistance when air passes into the internal chamber 31 and at the same time provides a reliable air current into and out of the chamber. This is very important especially as the smoke detection chamber and the overall size of the smoke alarm is very small. For larger smoke chambers the smoke filled airs access to the chamber is relatively easy achieved due to the prior art alarms size, but in order to obtain a fast reacting and reliable alarm of a compact size as is the case and object with the present invention, it has proven important to provide the smoke chamber with specially shaped air-foils. Turning to figure 5 the light emitting element 3 is illustrated, i.e. the activating member 1 has been removed in order to allow a view to the piezo electrical element 9. Furthermore, the helical springs 26 biasing the activating member 1 away from the contact points 8 (see figure 2) are also illustrated. The light element 3 provided with the light transmission means 23 is in this embodiment clearly indicated as penetrating through apertures 23' provided in the bottom plate 4.

In figure 6 is indicated an illustration similar to figure 5 where, however, the piezo electrical element 9 has been removed in order to expose the ventilated bottom plate 4. The ventilating apertures 21 are clearly seen here.

Turning to figure 7 a further embodiment of the invention is illustrated where the same reference numbers are used for same or corresponding features as mentioned above.

In figures 7-9 is illustrated a smoke detect or/alarm having the same features as discussed above, but with a special design allowing the smoke alarm to be installed as a rose around a wire, for example in a ceiling and lamp fitting. The smoke detector 50 has a centrally located through-going aperture 51 allowing an electrical wire to pass through the smoke detector 50. The activating button is arranged displaced from the central section, but still surrounded by a light emitting member 3' . Furthermore, the aperture 2' provided in the activating member is in this embodiment in the shape of three elongated grooves where further elongated grooves 52 are provided in other sec- tions of the top section 53 of the smoke detector. The elongated grooves 52 as well as the apertures 2' provide the possibility to vacuum clean the inside of the smoke detector, for example by placing the inlet of the vacuum cleaner over the activating member 1 ' thereby creating an air- flow through the elongated apertures 52 into the smoke detector and out through the apertures 2' in the activating member.

In figure 8 the top part of the smoke detector is removed, i.e. the top part corresponding to the activating button thereby exposing the internal smoke detecting chamber 30 where air-foils 7 are arranged along the periphery. The necessary electronics for controlling and driving the smoke detector are arranged around a central pipe 54 which centrally placed pipe 54 is superposed the aperture 51 as is evident from figure 9 whereby it is possible to thread for example an electrical wire through the entire smoke detector whereby the smoke detector may be positioned as a rose in a ceiling construction.

Various embodiments of arranging the activating member in the device is contemplated. In a first embodiment the entire top surface may be used as activating button. In this embodiment aperture 51 is axially distanced from the pipe 54 allowing the activating member to be depressed without meeting resistance from the pipe. The aper- ture 51 may also have a dimension slightly larger than the pipe 54, such that the aperture and pipe may move coaxially one outside the other. A further arrangement is contemplated where the activating button is arranged off-center, not interfering with the pipe 54 and aperture 51. The same features are depicted from a slightly different angle and in a cross section in figure 9.

Turning to further embodiments of the invention as depicted in figures 10 and 11 the activating button is incorporated in a heat sensor. The heat sensor 60 is in figure 10 depicted as having a mounting bracket 61 into which the unit itself 62 is positioned. The bracket 61 may by means of screws 63 or the like be mounted in the desired position. The heat sensor is provided with a probe 64 which is connected to suitable electronics (not illustrated) where said electronics will be able to translate the sensor's readings of the ambient environment. The probe 64 is protected by a number of but- tresses 65 which extend from the periphery of the member towards a centrally placed protection plate 66 arranged substantially centrally and above the sensor probe 64. In this manner the sensor probe is physically protected from impact by the buttresses 65 and the central plate 66. As is more clearly illustrated in figure 11, the temperature probe 64 is not in contact with the activating member 1 and it is therefore possible to mechanically depress the activating member 1 in the same manner as described above with reference to the other described embodiments of the invention. Likewise, a ventilated bottom plate 4 is provided, and between the bottom plate and the activating member is arranged a piezo electrical element 9 which will be able to generate the desired alarm signal. In this embodiment a light emitting element is not provided. The activating button according to the invention has now been explained with reference to a few possible embodiments wherein an activating button according to the invention may be incorporated, but it is clear that the scope of protection shall only be limited by the scope of the appended claims.

Claims

Activating button with integrated sound/noise generator, where said button comprises:

a ventilated bottom plate (4) having one or more apertures (21);

an activating member (6), which activating member (6) has at least one activating means (7) arranged on an underside of said activating member's top surface, which activating means (7) may be brought into contact with at least one contact point (8), and where said activating member's top surface is provided with an aperture (2),

a sound/noise generator having a sound chamber (20) delimited by a piezo electrical loudspeaker element (9) and the underside of the top surface of the activating member (6), and the piezo electrical loudspeaker element (9) and the ventilated bottom plate (4) allowing access to an inner volume of the device in which the sound button (1) is integrated such that sound may escape through the aperture (2) in the top surface (6) and the ventilated bottom plate (4) and into the device and to the ambient surroundings, where said piezo electrical loudspeaker (9) is arranged above the bottom plate (4);

an electrical connection between said contact point (8) and said piezo electrical loudspeaker (9).

The button according to claim 1, wherein the activating member is in the shape of one or more pins projecting from the underside of the top surface towards the bottom plate, and where spring means are arranged for biasing the activating means away from the bottom plate, where means are provided delimiting the activating member's travel relative to the bottom plate, such that the spring means when the button is not activated urges the activating member into a position furthest away from said bottom plate. 3. The button according to claim 1 or 2 wherein the button in a plane view is circular, oval, polygonal or any other geometrical shape, and where a light element is provided along the periphery of the button. The button according to claim 3, where the light element is made from a light transmitting material, which light element has light conducting pins extending towards the bottom plate, and where close to or adjacent distal ends of the light conducting pins LED elements are provided.

The button according to claim 1 wherein the aperture comprises one or more openings, and where said openings are arranged in a position making it possible to vacuum clean the interior of the device through said openings.

The button according to any preceding claim, wherein the contact point (8) either is arranged on the bottom plate (4) or an aperture is provided in said bottom plate such that the activating means (7) may project through the bottom plate (4) in order to be able to be brought into contact with the contact point (8).

Smoke detector having at least one internal chamber, which chamber has at least one opening towards the surroundings, such that air may pass through the chamber, and where means are provided for emitting light and means for detecting said light is provided in or around said chamber, where the change in light intensity registered by the means generates a smoke alarm, by means of a noise and/or light generating means and where the internal chamber is substantially circular, and that the light emitting means are arranged at an angle to the light detecting source, where along the periphery of the chamber a plurality of air foils are arranged, where the airfoils substantially have a cross-sectional shape corresponding to an airplane wing with one side of the air foils flat and the other side being provided with a curvature, and where said airfoils are arranged at an angle relative to an imaginary radius of the internal chamber, and where said noise generating means are provided in a button according to any of claims 1 to 6.

Smoke detector according to claim 7, where said smoke detector has a base plate, suitable to be mounted in a holder or directly on a surface, wherein substantially centrally in the smoke detector a through-going opening is provided, where said opening comprises a first pipe section arranged substantial- ly perpendicular to said base plate, and coaxially with said first pipe section the top surface of the activating button is provided with a second pipe section extending towards the base plate where said first and second pipe sections overlap and are displaceable along the pipes' axis.

Temperature alarm incorporating an activating button according to any of claims 1 to 6, wherein a temperature probe extends from said top surface, and where protective buttresses converge from the periphery of the top surface to a central protective member overlying the temperature probe.

Method of providing an alarm device with a noise generator, where said noise generator is integrated in a button device built into the alarm device, where said noise generator is a substantially flat piezo electrical element arranged in a sound chamber, said sound chamber having ventilation on both planar surfaces of the piezo electrical element.